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  • richardmitnick 1:57 pm on July 7, 2018 Permalink | Reply
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    From MIT News: “Project to elucidate the structure of atomic nuclei at the femtoscale” 

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    From MIT News

    July 6, 2018
    Scott Morley | Laboratory for Nuclear Science

    1
    The image is an artist’s visualization of a nucleus as studied in numerical simulations, created using DeepArt neural network visualization software. Image courtesy of the Laboratory for Nuclear Science.

    Laboratory for Nuclear Science project selected to explore machine learning for lattice quantum chromodynamics.

    The Argonne Leadership Computing Facility (ALCF), a U.S. Department of Energy (DOE) Office of Science User Facility, has selected 10 data science and machine learning projects for its Aurora Early Science Program (ESP). Set to be the nation’s first exascale system upon its expected 2021 arrival, Aurora will be capable of performing a quintillion calculations per second, making it 10 times more powerful than the fastest computer that currently exists.

    Depiction of ANL ALCF Cray Shasta Aurora supercomputer

    The Aurora ESP, which commenced with 10 simulation-based projects in 2017, is designed to prepare key applications, libraries, and infrastructure for the architecture and scale of the exascale supercomputer. Researchers in the Laboratory for Nuclear Science’s Center for Theoretical Physics have been awarded funding for one of the projects under the ESP. Associate professor of physics William Detmold, assistant professor of physics Phiala Shanahan, and principal research scientist Andrew Pochinsky will use new techniques developed by the group, coupling novel machine learning approaches and state-of-the-art nuclear physics tools, to study the structure of nuclei.

    Shanahan, who began as an assistant professor at MIT this month, says that the support and early access to frontier computing that the award provides will allow the group to study the possible interactions of dark matter particles with nuclei from our fundamental understanding of particle physics for the first time, providing critical input for experimental searches aiming to unravel the mysteries of dark matter while simultaneously giving insight into fundamental particle physics.

    “Machine learning coupled with the exascale computational power of Aurora will enable spectacular advances in many areas of science,” Detmold adds. “Combining machine learning to lattice quantum chromodynamics calculations of the strong interactions between the fundamental particles that make up protons and nuclei, our project will enable a new level of understanding of the femtoscale world.”

    See the full article here .


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  • richardmitnick 5:38 pm on June 11, 2018 Permalink | Reply
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    From MIT News: “3 Questions: Pinning down a neutrino’s mass” 

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    From MIT News

    June 8, 2018
    Jennifer Chu

    1
    The Karlsruhe Tritium Neutrino Experiment, or KATRIN, is a massive detector based in the town of Karlsruhe, Germany, that has been designed to measure a neutrino’s mass with far greater precision than existing experiments. Image: Karlsruhe/KIT Katrin

    KIT Katrin experiment

    KATRIN Experiment schematic

    Neutrinos are everywhere, and yet their presence is rarely felt. Scientists have assumed for decades that, because they interact so little with matter, neutrinos must lack any measurable mass. But recent experiments have shown that these “ghostly” particles do in fact hold some weight. Ever since, the hunt has been on to pin down a neutrino’s mass — a vanishingly small measurement that could have huge implications for our understanding of how the universe has evolved.

    Today, a major experiment has joined this fundamental search. The Karlsruhe Tritium Neutrino Experiment, or KATRIN, is a massive detector based in the town of Karlsruhe, Germany, that has been designed to measure a neutrino’s mass with far greater precision than existing experiments. At KATRIN’s heart is a 200-ton, zeppelin-like spectrometer, and scientists hope that with the experiment launching today they can start to collect data that in the next few years will give them a better idea of just how massive neutrinos can be.

    Professor of physics Joseph Formaggio is part of the team of scientists that will get a first look at KATRIN’s data as they come in. Formaggio and others from MIT helped construct part of the detector’s apparatus and developed software to simulate the trajectory of particles passing through the detector. His group is now working along with a team of scientists around the world on software to analyze the data for signs of neutrino mass. MIT News sat down with Formaggio ahead of the experiment’s launch, for a chat about KATRIN and the monumental structure built to search for an infinitesimal signal.

    Q: How will KATRIN measure the mass of a neutrino?

    A: KATRIN is addressing a very old question, one that was posed by [Enrico] Fermi in the 1930s, which is the question of how much mass a neutrino has. Decades ago, we thought the neutrino had to be massless. Then experiments in neutrino oscillations showed that no, that wasn’t actually true — neutrinos actually have a tiny mass. And now we know that different neutrinos have different masses from each other. What we don’t know is how much any one neutrino weighs — the absolute mass is still unknown.

    KATRIN addresses this question by looking at energy conservation: E = mc2. We have a radioactive gas, in this case, tritium, that releases energy as it decays. Some of that energy goes to a neutrino, which flies off and we never see it again. Some of that energy goes to an electron, and if you measure the electron’s energy very precisely, it turns out that tells you how much the neutrino took away. And in particular, was that energy all kinetic, because the neutrino was going away at the speed of light? Or does it have a little bit of rest energy, or mass?

    The experiment itself is about 70 meters long — almost a football field but not quite. Tritium is injected at one end, into a windowless tube, where there are millions of decays happening per second, all of which will produce electrons. The gas sits inside a magnet, and the electrons, because they’re charged, see this magnetic field, and they begin to follow the magnetic field lines out of the gas region and into a huge spectrometer — one of the largest vacuums in the world. The magnetic field is very weak in the spectrometer, and the field lines will start to spread out. The spectrometer is held at an electric potential of nearly 20,000 volts, which acts like a hill: Electrons that have enough energy will make it over this hill and come out the other side of the spectrometer. The ones that don’t have enough energy get turned back.

    Then there’s another set of magnets at the very end of this long beam line, where the field lines get tighter, the electrons focus back in, and they land on a detector that just counts electrons. This is a very precise way of scanning electron energies from this very hot, radioactive source. And that’s what allows us to get the energy resolution we need, to say something about neutrino mass.

    Q: What is the current estimate for a neutrino’s mass, and how will you know you’ve reached an even more precise measurement?

    A: We have some idea of what the neutrino mass scale should be. Previous experiments have told us that it’s somewhere between 10 millielectronvolts and 2 electronvolts. An electron, which is the other lightest particle that we know about, has a mass of about 511,000 electronvolts. So somewhere between 10 meV and 2eV is our playground.

    If the neutrino does have a mass, what does it look like in our experiment? What we do is we image the spectrum of electron energies. If the neutrino has a mass, it looks like a kink in our spectrum. So we look for that kink, which would mean that the neutrino has both kinetic energy, which we expect, but also rest energy. If it were all kinetic, then it has no mass, and it’s zipping along at the speed of light. If you observe a kink, it’s as if you made a neutrino that stood still. Things can’t stay still if they are massless. The kink is evidence that you produce just a few neutrinos that were standing still. You didn’t see them directly, but you saw the electron didn’t take the energy that it was supposed to, and that energy went into the neutrino.

    Q: In what ways would a more precise neutrino mass change our understanding of the universe?

    A: For other particles like the top quark and the electron, we might not understand why they have the masses they do, but we understand how they have mass. For the neutrino, that’s an open question. How the neutrino gets its mass is unknown. The hope is, by measuring the mass of the neutrino, you get a better sense of how a neutrino gets its mass. We have billions of neutrinos everywhere in the universe. If all of a sudden they have a mass, they will impact how the universe will evolve over time. For cosmologists, that information will be very useful.

    So there’s a little bit of, what’s going to happen when we actually make a measurement? Will we see something massive? There is a possibility for surprise, and that could be most exciting, because it would mean we really don’t understand what we’re doing, and that’s usually good for us.

    This is a long experiment coming. I joined the experiment when I was a postdoc in 2003, and there were people thinking about it even before then. It’s taken a long time, and it’s an incredible marvel of engineering. Because each time, they’ve had to solve a problem that didn’t have a solution yet. How do you build a tank of that size, and evacuate it so that it’s in vacuum? The tank is empty. Of air! And it’s a huge tank, one of the largest vacuums in the world. That’s an engineering feat. How do you keep the radioactive gas cold and stable to a few millikelvin? All these things really took a lot of engineering, and it’s a beautiful experiment. Now we get to take data, and that’s going to be very exciting.

    See the full article here .


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  • richardmitnick 5:23 pm on June 11, 2018 Permalink | Reply
    Tags: , , Graphene yet again, MIT, Monitoring electromagnetic radiation, , The graphene is coupled to a device called a photonic nanocavity   

    From MIT News: “A better device for measuring electromagnetic radiation” 

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    From MIT News

    June 11, 2018
    David Chandler

    1
    Schematic illustration of the experimental setup. Image courtesy of the researchers

    New bolometer is faster, simpler, and covers more wavelengths.

    Bolometers, devices that monitor electromagnetic radiation through heating of an absorbing material, are used by astronomers and homeowners alike. But most such devices have limited bandwidth and must be operated at ultralow temperatures. Now, researchers say they’ve found a ultrafast yet highly sensitive alternative that can work at room temperature — and may be much less expensive.

    The findings, published today in the journal Nature Nanotechnology, could help pave the way toward new kinds of astronomical observatories for long-wavelength emissions, new heat sensors for buildings, and even new kinds of quantum sensing and information processing devices, the multidisciplinary research team says. The group includes recent MIT postdoc Dmitri Efetov, Professor Dirk Englund of MIT’s Department of Electrical Engineering and Computer Science, Kin Chung Fong of Raytheon BBN Technologies, and colleagues from MIT and Columbia University.

    “We believe that our work opens the door to new types of efficient bolometers based on low-dimensional materials,” says Englund, the paper’s senior author. He says the new system, based on the heating of electrons in a small piece of a two-dimensional form of carbon called graphene, for the first time combines both high sensitivity and high bandwidth — orders of magnitude greater than that of conventional bolometers — in a single device.

    “The new device is very sensitive, and at the same time ultrafast,” having the potential to take readings in just picoseconds (trillionths of a second), says Efetov, now a professor at ICFO, the Institute of Photonic Sciences in Barcelona, Spain, who is the paper’s lead author. “This combination of properties is unique,” he says.

    The new system also can operate at any temperature, he says, unlike current devices that have to be cooled to extremely low temperatures. Although most actual applications of the device would still be done under these ultracold conditions, for some applications, such as thermal sensors for building efficiency, the ability to operate without specialized cooling systems could be a real plus. “This is the first device of this kind that has no limit on temperature,” Efetov says.

    The new bolometer they built, and demonstrated under laboratory conditions, can measure the total energy carried by the photons of incoming electromagnetic radiation, whether that radiation is in the form of visible light, radio waves, microwaves, or other parts of the spectrum. That radiation may be coming from distant galaxies, or from the infrared waves of heat escaping from a poorly insulated house.

    The device is entirely different from traditional bolometers, which typically use a metal to absorb the radiation and measure the resulting temperature rise. Instead, this team developed a new type of bolometer that relies on heating electrons moving in a small piece of graphene, rather than heating a solid metal. The graphene is coupled to a device called a photonic nanocavity, which serves to amplify the absorption of the radiation, Englund explains.

    “Most bolometers rely on the vibrations of atoms in a piece of material, which tends to make their response slow,” he says. In this case, though, “unlike a traditional bolometer, the heated body here is simply the electron gas, which has a very low heat capacity, meaning that even a small energy input due to absorbed photons causes a large temperature swing,” making it easier to make precise measurements of that energy. Although graphene bolometers had previously been demonstrated, this work solves some of the important outstanding challenges, including efficient absorption into the graphene using a nanocavity, and the impedance-matched temperature readout.

    The new technology, Englund says, “opens a new window for bolometers with entirely new functionalities that could radically improve thermal imaging, observational astronomy, quantum information, and quantum sensing, among other applications.”

    For astronomical observations, the new system could help by filling in some of the remaining wavelength bands that have not yet had practical detectors to make observations, such as the “terahertz gap” of frequencies that are very difficult to pick up with existing systems. “There, our detector could be a state-of-the-art system” for observing these elusive rays, Efetov says. It could be useful for observing the very long-wavelength cosmic background radiation, he says.

    Daniel Prober, a professor of applied physics at Yale University who was not involved in this research, says, “This work is a very good project to utilize the many benefits of the ultrathin metal layer, graphene, while cleverly working around the limitations that would otherwise be imposed by its conducting nature.” He adds, “The resulting detector is extremely sensitive for power detection in a challenging region of the spectrum, and is now ready for some exciting applications.”

    And Robert Hadfield, a professor of photonics at the University of Glasgow, who also was not involved in this work, says, “There is huge demand for new high-sensitivity infrared detection technologies. This work by Efetov and co-workers reporting an innovative graphene bolometer integrated in a photonic crystal cavity to achieve high absorption is timely and exciting.”

    See the full article here .


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  • richardmitnick 10:43 am on May 4, 2018 Permalink | Reply
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    From MIT News: “Ushering in the next phase of exoplanet discovery” 

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    May 3, 2018
    Lauren Hinkel | Oceans at MIT

    NASA/TESS

    1
    “TESS is trying to take everything that people have already done and do it better and do it across the whole sky,” says Sara Seager, the Class of 1941 Professor at MIT.
    Photo: Justin Knight.

    2
    TESS will survey the sky in a series of 13 observing segments, each 27-days long. It will spend the first year on the southern ecliptic hemisphere and the second year on the northern ecliptic hemisphere. Depending on sky position, TESS targets will be observed for a minimum of 27 days up to a maximum of 351 days. Image: Roland Vanderspek.

    Professor Sara Seager previews a new era of discovery as a leader of the TESS mission, which is expected to find some 20,000 extrasolar planets.


    A SpaceX Falcon 9 rocket lifted off on April 18 from Cape Canaveral Air Force Station carrying NASA’s Transiting Exoplanet Survey Satellite, or TESS. The MIT-led mission is the next step in the search for planets outside of the solar system and orbiting other nearby stars. The mission is designed to find exoplanets by blocking their light while the planets transition across. Video: NASA

    Ever since scientists discovered the first planet outside of our solar system, 51 Pegasi b, the astronomical field of exoplanets has exploded, thanks in large part to the Kepler Space Telescope.

    NASA/Kepler Telescope

    Now, with the successful launch of the Transiting Exoplanet Survey Satellite (TESS), Professor Sara Seager sees a revolution not only in the amount of new planetary data to analyze, but also in the potential for new avenues of scientific discovery.

    “TESS is going to essentially provide the catalog of all of the best planets for following up, for observing their atmospheres and learning more about them,” Seager says. “But it would be impossible to really describe all the different things that people are hoping to do with the data.”

    For Seager, the goal is to sift through the plethora of incoming TESS data to identify exoplanet candidates. Ultimately, she says she wants to find the best planets to follow up with atmosphere studies for signs that the planet might be suitable for life.

    “When I came to MIT 10 years ago, [MIT scientists] were starting to work on TESS, so that was the starting point,” said Seager, the Class of 1941 Professor Chair in MIT’s Department of Earth, Atmospheric and Planetary Sciences with appointments in the departments of Physics and Aeronautics and Astronautics.

    Seager is the deputy science director of TESS, an MIT-led NASA Explorer-class mission. Her credentials include pioneering exoplanet characterization, particularly of atmospheres, that form the foundation of the field. Seager is currently hunting for exoplanets with signs of life, and TESS is the next step on that path.

    So far, scientists have confirmed 3,717 exoplanets in 2,773 systems. As an all-sky survey, TESS will build on this, observing 85 percent of the cosmos containing more than 200,000 nearby stars, and researchers expect to identify some 20,000 exoplanets.

    “TESS is trying to take everything that people have already done and do it better and do it across the whole sky,” Seager says. While this mission relies on exoplanet hunting techniques developed years ago, the returns on this work should extend far into the future.

    Planet transit. NASA/Ames

    Radial Velocity Method-Las Cumbres Observatory

    Radial velocity Image via SuperWasp http http://www.superwasp.org-exoplanets.htm

    Direct imaging-This false-color composite image traces the motion of the planet Fomalhaut b, a world captured by direct imaging.

    “TESS is almost the culmination of a couple of decades of hard work, trying to iron out the wrinkles of how to find planets by the transiting method. So, TESS isn’t changing the way we look for planets, more like it’s riding on the wave of success of how we’ve done it already.”

    The TESS science leadership team have committed to delivering at least 50 exoplanets with radii less than four times that of Earth’s along with measured masses. As part of the TESS mission, an international effort to further characterize the planet candidates and their host stars down to the list of 50 with measured masses will be ongoing, using the best ground-based telescopes available.

    For the best exoplanets for follow up, Seager likens photons reaching the satellite’s cameras to money: the more photons you have, the better. Accordingly, the cameras are optimized for nearby, bright stars. Furthermore, the cameras are calibrated to favor small, red M dwarf stars, around which small planets with a rocky surface are more easily detected than around the larger, yellow sun-size stars. Additionally, researchers tuned the satellite to exoplanets with orbits of less than 13 days, so that two transits are used for discovery.

    See the full article here .

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  • richardmitnick 10:59 am on April 21, 2018 Permalink | Reply
    Tags: , How to bend and stretch a diamond, , MIT,   

    From MIT: “How to bend and stretch a diamond” 

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    April 19, 2018
    David L. Chandler

    2
    (Stellar-Serbia/iStock) via Science Alert

    1
    This scanning electron microscope image shows ultrafine diamond needles (cone shapes rising from bottom) being pushed on by a diamond tip (dark shape at top). These images reveal that the diamond needles can bend as much as 9 percent and still return to their original shape. Courtesy of the researchers.

    The brittle material can turn flexible when made into ultrafine needles, researchers find.

    Diamond is well-known as the strongest of all natural materials, and with that strength comes another tightly linked property: brittleness. But now, an international team of researchers from MIT, Hong Kong, Singapore, and Korea has found that when grown in extremely tiny, needle-like shapes, diamond can bend and stretch, much like rubber, and snap back to its original shape.

    The surprising finding is being reported this week in the journal Science, in a paper by senior author Ming Dao, a principal research scientist in MIT’s Department of Materials Science and Engineering; MIT postdoc Daniel Bernoulli; senior author Subra Suresh, former MIT dean of engineering and now president of Singapore’s Nanyang Technological University; graduate students Amit Banerjee and Hongti Zhang at City University of Hong Kong; and seven others from CUHK and institutions in Ulsan, South Korea.

    3
    Experiment (left) and simulation (right) of a diamond nanoneedle being bent by the side surface of a diamond tip, showing ultralarge and reversible elastic deformation. No image credit.

    The results, the researchers say, could open the door to a variety of diamond-based devices for applications such as sensing, data storage, actuation, biocompatible in vivo imaging, optoelectronics, and drug delivery. For example, diamond has been explored as a possible biocompatible carrier for delivering drugs into cancer cells.

    The team showed that the narrow diamond needles, similar in shape to the rubber tips on the end of some toothbrushes but just a few hundred nanometers (billionths of a meter) across, could flex and stretch by as much as 9 percent without breaking, then return to their original configuration, Dao says.

    Ordinary diamond in bulk form, Bernoulli says, has a limit of well below 1 percent stretch. “It was very surprising to see the amount of elastic deformation the nanoscale diamond could sustain,” he says.

    “We developed a unique nanomechanical approach to precisely control and quantify the ultralarge elastic strain distributed in the nanodiamond samples,” says Yang Lu, senior co-author and associate professor of mechanical and biomedical engineering at CUHK. Putting crystalline materials such as diamond under ultralarge elastic strains, as happens when these pieces flex, can change their mechanical properties as well as thermal, optical, magnetic, electrical, electronic, and chemical reaction properties in significant ways, and could be used to design materials for specific applications through “elastic strain engineering,” the team says.

    The team measured the bending of the diamond needles, which were grown through a chemical vapor deposition process and then etched to their final shape, by observing them in a scanning electron microscope while pressing down on the needles with a standard nanoindenter diamond tip (essentially the corner of a cube). Following the experimental tests using this system, the team did many detailed simulations to interpret the results and was able to determine precisely how much stress and strain the diamond needles could accommodate without breaking.

    The researchers also developed a computer model of the nonlinear elastic deformation for the actual geometry of the diamond needle, and found that the maximum tensile strain of the nanoscale diamond was as high as 9 percent. The computer model also predicted that the corresponding maximum local stress was close to the known ideal tensile strength of diamond — i.e. the theoretical limit achievable by defect-free diamond.

    When the entire diamond needle was made of one crystal, failure occurred at a tensile strain as high as 9 percent. Until this critical level was reached, the deformation could be completely reversed if the probe was retracted from the needle and the specimen was unloaded. If the tiny needle was made of many grains of diamond, the team showed that they could still achieve unusually large strains. However, the maximum strain achieved by the polycrystalline diamond needle was less than one-half that of the single crystalline diamond needle.

    Yonggang Huang, a professor of civil and environmental engineering and mechanical engineering at Northwestern University, who was not involved in this research, agrees with the researchers’ assessment of the potential impact of this work. “The surprise finding of ultralarge elastic deformation in a hard and brittle material — diamond — opens up unprecedented possibilities for tuning its optical, optomechanical, magnetic, phononic, and catalytic properties through elastic strain engineering,” he says.

    Huang adds “When elastic strains exceed 1 percent, significant material property changes are expected through quantum mechanical calculations. With controlled elastic strains between 0 to 9 percent in diamond, we expect to see some surprising property changes.”

    The team also included Muk-Fung Yuen, Jiabin Liu, Jian Lu, Wenjun Zhang, and Yang Lu at the City University of Hong Kong; and Jichen Dong and Feng Ding at the Institute for Basic Science, in South Korea. The work was funded by the Research Grants Council of the Hong Kong Special Administrative Region, Singapore-MIT Alliance for Rresearch and Technology (SMART), Nanyang Technological University Singapore, and the National Natural Science Foundation of China.

    See the full article here .

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  • richardmitnick 11:15 am on April 13, 2018 Permalink | Reply
    Tags: MIT, MIT led NASA High Energy Transient Explorer 2HETE 2 NASA,   

    From MIT: “TESS readies for takeoff” 

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    April 12, 2018
    Jennifer Chu

    1
    A set of flight camera electronics on one of the TESS cameras, developed by the MIT Kavli Institute for Astrophysics and Space Research (MKI), will transmit exoplanet data from the camera to a computer aboard the spacecraft that will process it before transmitting it back to scientists on Earth. Image: MIT Kavli Institute.

    2
    NASA’s Transiting Exoplanet Survey Satellite (TESS), shown here in a conceptual illustration, will identify exoplanets orbiting the brightest stars just outside our solar system. TESS will search for exoplanets orbiting stars within hundreds of light-years of our solar system. Looking at these close, bright stars will allow large ground-based telescopes and the James Webb Space Telescope to do follow-up observations on the exoplanets TESS finds to characterize their atmospheres. Image: NASA’s Goddard Space Flight Center.

    3
    NASA’s Transiting Exoplanet Survey Satellite (TESS), shown here in a conceptual illustration, will identify exoplanets orbiting the brightest stars just outside our solar system. Image: NASA’s Goddard Space Flight Center.

    Satellite developed by MIT aims to discover thousands of nearby exoplanets, including at least 50 Earth-sized ones.

    There are potentially thousands of planets that lie just outside our solar system — galactic neighbors that could be rocky worlds or more tenuous collections of gas and dust. Where are these closest exoplanets located? And which of them might we be able to probe for clues to their composition and even habitability? The Transiting Exoplanet Survey Satellite (TESS) will be the first to seek out these nearby worlds.

    The NASA-funded spacecraft, not much larger than a refrigerator, carries four cameras that were conceived, designed, and built at MIT, with one wide-eyed vision: to survey the nearest, brightest stars in the sky for signs of passing planets.

    Now, more than a decade since MIT scientists first proposed the mission, TESS is about to get off the ground. The spacecraft is scheduled to launch on a SpaceX Falcon 9 rocket from Cape Canaveral Air Force Station in Florida, no earlier than April 16, at 6:32 p.m. EDT.

    4
    The Transiting Exoplanet Survey Satellite (TESS) will discover thousands of exoplanets in orbit around the brightest stars in the sky. In a two-year survey of the solar neighborhood, TESS will monitor more than 200,000 stars for temporary drops in brightness caused by planetary transits. This first-ever space borne all-sky transit survey will identify planets ranging from Earth-sized to gas giants, around a wide range of stellar types and orbital distances. No ground-based survey can achieve this feat. (NASA’s Goddard Space Flight Center/CI Lab).

    TESS will spend two years scanning nearly the entire sky — a field of view that can encompass more than 20 million stars. Scientists expect that thousands of these stars will host transiting planets, which they hope to detect through images taken with TESS’s cameras.

    Amid this extrasolar bounty, the TESS science team at MIT aims to measure the masses of at least 50 small planets whose radii are less than four times that of Earth. Many of TESS’s planets should be close enough to our own that, once they are identified by TESS, scientists can zoom in on them using other telescopes, to detect atmospheres, characterize atmospheric conditions, and even look for signs of habitability.

    “TESS is kind of like a scout,” says Natalia Guerrero, deputy manager of TESS Objects of Interest, an MIT-led effort that will catalog objects captured in TESS data that may be potential exoplanets.

    “We’re on this scenic tour of the whole sky, and in some ways we have no idea what we will see,” Guerrero says. “It’s like we’re making a treasure map: Here are all these cool things. Now, go after them.”

    A seed, planted in space

    TESS’s origins arose from an even smaller satellite that was designed and built by MIT and launched into space by NASA on Oct. 9, 2000. The High Energy Transient Explorer 2, or HETE-2, orbited Earth for seven years, on a mission to detect and localize gamma-ray bursts — high-energy explosions that emit massive, fleeting bursts of gamma and X-rays.

    MIT led NASA High Energy Transient Explorer 2HETE 2 NASA

    To detect such extreme, short-lived phenomena, scientists at MIT, led by principal investigator George Ricker, integrated into the satellite a suite of optical and X-ray cameras outfitted with CCDs, or charge-coupled devices, designed to record intensities and positions of light in an electronic format.

    “With the advent of CCDs in the 1970s, you had this fantastic device … which made a lot of things easier for astronomers,” says HETE-2 team member Joel Villasenor, who is now also instrument scientist for TESS. “You just sum up all the pixels on a CCD, which gives you the intensity, or magnitude, of light. So CCDs really broke things open for astronomy.”

    In 2004, Ricker and the HETE-2 team wondered whether the satellite’s optical cameras could pick out other objects in the sky that had begun to attract the astronomy community: exoplanets. Around this time, fewer than 200 planets outside our solar system had been discovered. A few of these were found with a technique known as the transit method, which involves looking for periodic dips in the light from certain stars, which may signal a planet passing in front of the star.

    “We were thinking, was the photometry of HETE-2’s cameras sufficient so that we could point to a part of the sky and detect one of these dips? Needless to say, it didn’t exactly work,” Villasenor recalls. “But that was sort of the seed that started us thinking, maybe we should try to fly CCDs with a camera to try and detect these things.”

    A path, cleared

    In 2006, Ricker and his team at MIT proposed a small, low cost satellite (HETE-S) to NASA as a Discovery class mission, and later on as a privately funded mission for $20 million. But as the cost of, and interest in, an all-sky exoplanet survey grew, they decided instead to seek NASA funding, at a higher level of $120 million. In 2008, they submitted a proposal for a NASA Small Explorer (SMEX) Class Mission with the new name — TESS.

    At this time, the satellite design included six CCD cameras, and the team proposed that the spacecraft fly in a low-Earth orbit, similar to that of HETE-2. Such an orbit, they reasoned, should keep observing efficiency relatively high, as they already had erected data-receiving ground stations for HETE-2 that could also be put to use for TESS.

    But they soon realized that a low-Earth orbit would have a negative impact on TESS’s much more sensitive cameras. The spacecraft’s reaction to the Earth’s magnetic field, for example, could lead to significant “spacecraft jitter,” producing noise that hides an exoplanet’s telltale dip in starlight.

    NASA bypassed this first proposal, and the team went back to the drawing board, this time emerging with a new plan that hinged on a completely novel orbit. With the help of engineers from Orbital ATK, the Aerospace Corporation, and NASA’s Goddard Space Flight Center, the team identified a never-before-used “lunar-resonant” orbit that would keep the spacecraft extremely stable, while giving it a full-sky view.

    Once TESS reaches this orbit, it will slingshot between the Earth and the moon on a highly elliptical path that could keep TESS orbiting for decades, shepherded by the moon’s gravitational pull.

    “The moon and the satellite are in a sort of dance,” Villasenor says. “The moon pulls the satellite on one side, and by the time TESS completes one orbit, the moon is on the other side tugging in the opposite direction. The overall effect is the moon’s pull is evened out, and it’s a very stable configuration over many years. Nobody’s done this before, and I suspect other programs will try to use this orbit later on.”

    In its current planned trajectory, TESS will swing out toward the moon for less than two weeks, gathering data, then swing back toward the Earth where, on its closest approach, it will transmit the data back to ground stations from 67,000 miles above the surface before swinging back out. Ultimately, this orbit will save TESS a huge amount of fuel, as it won’t need to burn its thrusters on a regular basis to keep on its path.

    With this revamped orbit, the TESS team submitted a second proposal in 2010, this time as an Explorer class mission, which NASA approved in 2013. It was around this time that the Kepler Space Telescope ended its original survey for exoplanets. The observatory, which was launched in 2009, stared at one specific patch of the sky for four years, to monitor the light from distant stars for signs of transiting planets.

    By 2013, two of Kepler’s four reaction wheels had worn out, preventing the spacecraft from continuing its original survey. At this point, the telescope’s measurements had enabled the discovery of nearly 1,000 confirmed exoplanets. Kepler, designed to study far-off stars, paved the way for TESS, a mission with a much wider view, to scan the nearest stars to Earth.

    “Kepler went up, and was this huge success, and researchers said, ‘We can do this kind of science, and there are planets everywhere,” says TESS member Jennifer Burt, an MIT-Kavli postdoc. “And I think that was really the scientific check box that we needed for NASA to say, ‘Okay, TESS makes a lot of sense now.’ It’ll enable not just detecting planets, but finding planets that we can thoroughly characterize after the fact.”

    Stripes in the sky

    With the selection by NASA, the TESS team set up facilities on campus and in MIT’s Lincoln Laboratory to build and test the spacecraft’s cameras. The engineers designed “deep depletion” CCDs specifically for TESS, meaning that the cameras can detect light over a wide range of wavelengths up to the near infrared. This is important, as many of the nearby stars TESS will monitor are red-dwarfs — small, cool stars that emit less brightly than the sun and in the infrared part of the electromagnetic spectrum.

    If scientists can detect periodic dips in the light from such stars, this may signal the presence of planets with significantly tighter orbits than that of Earth. Nevertheless, there is a chance that some of these planets may be within the “habitable zone,” as they would circle much cooler stars, compared with the sun. Since these stars are relatively close by, scientists can do follow-up observations with ground-based telescopes to help identify whether conditions might indeed be suitable for life.

    TESS’s cameras are mounted on the top of the satellite and surrounded by a protective cone to shield them from other forms of electromagnetic radiation. Each camera has a 24 by 24 degree view of the sky, large enough to encompass the Orion constellation. The satellite will start its observations in the Southern Hemisphere and will divide the sky into 13 stripes, monitoring each segment for 27 days before pivoting to the next. TESS should be able to observe nearly the entire sky in the Southern Hemisphere in its first year, before moving on to the Northern Hemisphere in its second year.

    While TESS points at one stripe of the sky, its cameras will take pictures of the stars in that portion. Ricker and his colleagues have made a list of 200,000 nearby, bright stars that they would particularly want to observe. The satellite’s cameras will create “postage stamp” images that include pixels around each of these stars. These images will be taken every two minutes, in order to maximize the chance of catching the moment that a planet crosses in front of its star. The cameras will also take full-frame images of all the stars in a particular stripe of the sky, every 30 minutes.

    “With the two-minute pictures, you can get a movie-like image of what the starlight is doing as the planet is crossing in front of its host star,” Guerrero says. “For the 30-minute images, people are excited about maybe seeing supernovae, asteroids, or counterparts to gravitational waves. We have no idea what we’re going to see at that timescale.”

    Are we alone?

    After TESS launches, the team expects that the satellite will reestablish contact within the first week, during which it will turn on all its instruments and cameras. Then, there will be a 60-day commissioning phase, as engineers and scientists at Orbital ATK, NASA, and MIT calibrate the instruments and monitor the satellite’s trajectory and performance. After that, TESS will begin to collect and downlink images of the sky. Scientists at MIT and NASA will take the raw data and convert it into light curves that indicate the changing brightness of a star over time.

    From there, the TESS Science Team, including Sara Seager, the Class of 1941 Professor of Earth, Atmospheric and Planetary Sciences, and deputy director of science for TESS, will look through thousands of light curves, for at least two similar dips in starlight, indicating that a planet may have passed twice in front of its star. Seager and her colleagues will then employ a battery of methods to determine the mass of a potential planet.

    “Mass is a defining planetary characteristic,” Seager says. “If you just know that a planet is twice the size of Earth, it could be a lot of things: a rocky world with a thin atmosphere, or what we call a “mini-Neptune” — a rocky world with a giant gas envelope, where it would be a huge greenhouse blanket, and there would be no life on the surface. So mass and size together give us an average planet density, which tells us a huge amount about what the planet is.”

    During TESS’s two-year mission, Seager and her colleagues aim to measure the masses of 50 planets with radii less than four times that of Earth — dimensions that could signal further observations for signs of habitability. Meanwhile, the whole scientific community and public will get a chance to search through TESS data for their own exoplanets. Once the data are calibrated, the team will make them publicly available. Anyone will be able to download the data and draw their own interpretations, including high school students, armchair astronomers, and other research institutions.

    With so many eyes on TESS’S data, Seager says there’s a chance that, some day, a nearby planet discovered by TESS might be found to have signs of life.

    “There’s no science that will tell us life is out there right now, except that small rocky planets appear to be incredibly common,” Seager says. “They appear to be everywhere we look. So it’s got to be there somewhere.”

    TESS is a NASA Astrophysics Explorer mission led and operated by MIT in Cambridge, Massachusetts, and managed by NASA’s Goddard Space Flight Center in Greenbelt, Maryland. George Ricker of MIT’s Kavli Institute for Astrophysics and Space Research serves as principal investigator for the mission. Additional partners include Orbital ATK, NASA’s Ames Research Center, the Harvard-Smithsonian Center for Astrophysics, and the Space Telescope Science Institute. More than a dozen universities, research institutes, and observatories worldwide are participants in the mission.

    See the full article here .

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  • richardmitnick 5:24 pm on April 1, 2018 Permalink | Reply
    Tags: , , Computer searches telescope data for evidence of distant planets, , MIT   

    From MIT: “Computer searches telescope data for evidence of distant planets” 

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    March 29, 2018
    Larry Hardesty

    1
    A young sun-like star encircled by its planet-forming disk of gas and dust.
    Image: NASA/JPL-Caltech

    Machine-learning system uses physics principles to augment data from NASA crowdsourcing project.

    As part of an effort to identify distant planets hospitable to life, NASA has established a crowdsourcing project in which volunteers search telescopic images for evidence of debris disks around stars, which are good indicators of exoplanets.

    Using the results of that project, researchers at MIT have now trained a machine-learning system to search for debris disks itself. The scale of the search demands automation: There are nearly 750 million possible light sources in the data accumulated through NASA’s Wide-Field Infrared Survey Explorer (WISE) mission alone.

    NASA/WISE Telescope

    In tests, the machine-learning system agreed with human identifications of debris disks 97 percent of the time. The researchers also trained their system to rate debris disks according to their likelihood of containing detectable exoplanets. In a paper describing the new work in the journal Astronomy and Computing, the MIT researchers report that their system identified 367 previously unexamined celestial objects as particularly promising candidates for further study.

    The work represents an unusual approach to machine learning, which has been championed by one of the paper’s coauthors, Victor Pankratius, a principal research scientist at MIT’s Haystack Observatory. Typically, a machine-learning system will comb through a wealth of training data, looking for consistent correlations between features of the data and some label applied by a human analyst — in this case, stars circled by debris disks.

    But Pankratius argues that in the sciences, machine-learning systems would be more useful if they explicitly incorporated a little bit of scientific understanding, to help guide their searches for correlations or identify deviations from the norm that could be of scientific interest.

    “The main vision is to go beyond what A.I. is focusing on today,” Pankratius says. “Today, we’re collecting data, and we’re trying to find features in the data. You end up with billions and billions of features. So what are you doing with them? What you want to know as a scientist is not that the computer tells you that certain pixels are certain features. You want to know ‘Oh, this is a physically relevant thing, and here are the physics parameters of the thing.’”

    Classroom conception

    The new paper grew out of an MIT seminar that Pankratius co-taught with Sara Seager, the Class of 1941 Professor of Earth, Atmospheric, and Planetary Sciences, who is well-known for her exoplanet research. The seminar, Astroinformatics for Exoplanets, introduced students to data science techniques that could be useful for interpreting the flood of data generated by new astronomical instruments. After mastering the techniques, the students were asked to apply them to outstanding astronomical questions.

    For her final project, Tam Nguyen, a graduate student in aeronautics and astronautics, chose the problem of training a machine-learning system to identify debris disks, and the new paper is an outgrowth of that work. Nguyen is first author on the paper, and she’s joined by Seager, Pankratius, and Laura Eckman, an undergraduate majoring in electrical engineering and computer science.

    From the NASA crowdsourcing project, the researchers had the celestial coordinates of the light sources that human volunteers had identified as featuring debris disks. The disks are recognizable as ellipses of light with slightly brighter ellipses at their centers. The researchers also used the raw astronomical data generated by the WISE mission.

    To prepare the data for the machine-learning system, Nguyen carved it up into small chunks, then used standard signal-processing techniques to filter out artifacts caused by the imaging instruments or by ambient light. Next, she identified those chunks with light sources at their centers, and used existing image-segmentation algorithms to remove any additional sources of light. These types of procedures are typical in any computer-vision machine-learning project.

    Coded intuitions

    But Nguyen used basic principles of physics to prune the data further. For one thing, she looked at the variation in the intensity of the light emitted by the light sources across four different frequency bands. She also used standard metrics to evaluate the position, symmetry, and scale of the light sources, establishing thresholds for inclusion in her data set.

    In addition to the tagged debris disks from NASA’s crowdsourcing project, the researchers also had a short list of stars that astronomers had identified as probably hosting exoplanets. From that information, their system also inferred characteristics of debris disks that were correlated with the presence of exoplanets, to select the 367 candidates for further study.

    “Given the scalability challenges with big data, leveraging crowdsourcing and citizen science to develop training data sets for machine-learning classifiers for astronomical observations and associated objects is an innovative way to address challenges not only in astronomy but also several different data-intensive science areas,” says Dan Crichton, who leads the Center for Data Science and Technology at NASA’s Jet Propulsion Laboratory. “The use of the computer-aided discovery pipeline described to automate the extraction, classification, and validation process is going to be helpful for systematizing how these capabilities can be brought together. The paper does a nice job of discussing the effectiveness of this approach as applied to debris disk candidates. The lessons learned are going to be important for generalizing the techniques to other astronomy and different discipline applications.”

    “The Disk Detective science team has been working on its own machine-learning project, and now that this paper is out, we’re going to have to get together and compare notes,” says Marc Kuchner, a senior astrophysicist at NASA’s Goddard Space Flight Center and leader of the crowdsourcing disk-detection project known as Disk Detective. “I’m really glad that Nguyen is looking into this because I really think that this kind of machine-human cooperation is going to be crucial for analyzing the big data sets of the future.”

    See the full article here .

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  • richardmitnick 12:53 pm on March 29, 2018 Permalink | Reply
    Tags: , Gran Sasso National Laboratories (LNGS), Is the neutrino is its own antiparticle?, MIT,   

    From MIT News: “Scientists report first results from CUORE neutrino experiment” 

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    March 26, 2018
    Jennifer Chu

    1
    Researchers working on the cryostat. Image: CUORE Collaboration

    Data could shed light on why the universe has more matter than antimatter.

    This week, an international team of physicists, including researchers at MIT, is reporting the first results from an underground experiment designed to answer one of physics’ most fundamental questions: Why is our universe made mostly of matter?

    According to theory, the Big Bang should have produced equal amounts of matter and antimatter — the latter consisting of “antiparticles” that are essentially mirror images of matter, only bearing charges opposite to those of protons, electrons, neutrons, and other particle counterparts. And yet, we live in a decidedly material universe, made mostly of galaxies, stars, planets, and everything we see around us — and very little antimatter.

    Physicists posit that some process must have tilted the balance in favor of matter during the first moments following the Big Bang. One such theoretical process involves the neutrino — a particle that, despite having almost no mass and interacting very little with other matter, is thought to permeate the universe, with trillions of the ghostlike particles streaming harmlessly through our bodies every second.

    There is a possibility that the neutrino may be its own antiparticle, meaning that it may have the ability to transform between a matter and antimatter version of itself. If that is the case, physicists believe this might explain the universe’s imbalance, as heavier neutrinos, produced immediately after the Big Bang, would have decayed asymmetrically, producing more matter, rather than antimatter, versions of themselves.

    One way to confirm that the neutrino is its own antiparticle, is to detect an exceedingly rare process known as a “neutrinoless double-beta decay,” in which a stable isotope, such as tellurium or xenon, gives off certain particles, including electrons and antineutrinos, as it naturally decays. If the neutrino is indeed its own antiparticle, then according to the rules of physics the antineutrinos should cancel each other out, and this decay process should be “neutrinoless.” Any measure of this process should only record the electrons escaping from the isotope.

    The underground experiment known as CUORE, for the Cryogenic Underground Observatory for Rare Events, is designed to detect a neutrinoless double-beta decay from the natural decay of 988 crystals of tellurium dioxide.

    CUORE experiment,at the Italian National Institute for Nuclear Physics’ (INFN’s) Gran Sasso National Laboratories (LNGS) in Italy,a search for neutrinoless double beta decay

    In a paper published this week in Physical Review Letters, researchers, including physicists at MIT, report on the first two months of data collected by CUORE (Italian for “heart”). And while they have not yet detected the telltale process, they have been able to set the most stringent limits yet on the amount of time that such a process should take, if it exists at all. Based on their results, they estimate that a single atom of tellurium should undergo a neutrinoless double-beta decay, at most, once every 10 septillion (1 followed by 25 zeros) years.

    Taking into account the massive number of atoms within the experiment’s 988 crystals, the researchers predict that within the next five years they should be able to detect at least five atoms undergoing this process, if it exists, providing definitive proof that the neutrino is its own antiparticle.

    “It’s a very rare process — if observed, it would be the slowest thing that has ever been measured,” says CUORE member Lindley Winslow, a member of the Laboratory for Nuclear Science, and the Jerrold R. Zacharias Career Development Assistant Professor of Physics at MIT, who led the analysis. “The big excitement here is that we were able to run 998 crystals together, and now we’re on a path to try and see something.”

    The CUORE collaboration includes some 150 scientists primarily from Italy and the U.S., including Winslow and a small team of postdocs and graduate students from MIT.

    Coldest cube in the universe

    The CUORE experiment is housed underground, in the Italian National Institute for Nuclear Physics’ (INFN) Gran Sasso National Laboratories, buried deep within a mountain in central Italy, in order to shield it from external stimuli such as the constant bombardment of radiation from sources in the universe.

    Gran Sasso LABORATORI NAZIONALI del GRAN SASSO, located in the Abruzzo region of central Italy

    The heart of the experiment is a detector consisting of 19 towers, each containing 52 cube-shaped crystals of tellurium dioxide, totaling 988 crystals in all, with a mass of about 742 kilograms, or 1,600 pounds. Scientists estimate that this amount of crystals embodies around 100 septillion atoms of the particular tellurium isotope. Electronics and temperature sensors are attached to each crystal to monitor signs of their decay.

    The entire detector resides within an ultracold refrigerator, about the size of a vending machine, which maintains a steady temperature of 6 millikelvin, or -459.6 degrees Fahrenheit. Researchers in the collaboration have previously calculated that this refrigerator is the coldest cubic meter that exists in the universe.

    The experiment needs to be kept exceedingly cold in order to detect minute changes in temperature generated by the decay of a single tellurium atom. In a normal double-beta decay process, a tellurium atom gives off two electrons, as well as two antineutrinos, which amount to a certain energy in the form of heat. In the event of a neutrinoless double-beta decay, the two antineutrinos should cancel each other out, and only the energy released by the two electrons would be generated. Physicists have previously calculated that this energy must be around 2.5 megaelectron volts (Mev).

    In the first two months of CUORE’s operation, scientists have essentially been taking the temperature of the 988 tellurium crystals, looking for any miniscule spike in energy around that 2.5 Mev mark.

    “CUORE is like a gigantic thermometer,” Winslow says. “Whenever you see a heat deposit on a crystal, you end up seeing a pulse that you can digitize. Then you go through and look at these pulses, and the height and width of the pulse corresponds to how much energy was there. Then you zoom in and count how many events were at 2.5 Mev, and we basically saw nothing. Which is probably good because we weren’t expecting to see anything in the first two months of data.”

    The heart will go on

    The results more or less indicate that, within the short window in which CUORE has so far operated, not one of the 1,000 septillion tellurium atoms in the detector underwent a neutrinoless double-beta decay. Statistically speaking, this means that it would take at least 10 septillion years, or years, for a single atom to undergo this process if a neutrino is in fact its own antiparticle.

    “For tellurium dioxide, this is the best limit for the lifetime of this process that we’ve ever gotten,” Winslow says.

    CUORE will continue to monitor the crystals for the next five years, and researchers are now designing the experiment’s next generation, which they have dubbed CUPID — a detector that will look for the same process within an even greater number of atoms. Beyond CUPID, Winslow says there is just one more, bigger iteration that would be possible, before scientists can make a definitive conclusion.

    “If we don’t see it within 10 to 15 years, then, unless nature chose something really weird, the neutrino is most likely not its own antiparticle,” Winslow says. “Particle physics tells you there’s not much more wiggle room for the neutrino to still be its own antiparticle, and for you not to have seen it. There’s not that many places to hide.”

    This research is supported by the National Institute for Nuclear Physics (INFN) in Italy, the National Science Foundation, the Alfred P. Sloan Foundation, and the U.S. Department of Energy.

    See the full article here .

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  • richardmitnick 1:12 pm on March 11, 2018 Permalink | Reply
    Tags: , , , Eni, , MIT   

    From MIT: “A new era in fusion research at MIT” 

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    March 9, 2018
    Francesca McCaffrey | MIT Energy Initiative

    MIT Energy Initiative founding member Eni announces support for key research through MIT Laboratory for Innovation in Fusion Technologies.

    1

    A new chapter is beginning for fusion energy research at MIT.

    This week the Italian energy company Eni, a founding member of the MIT Energy Initiative (MITEI), announced it has reached an agreement with MIT to fund fusion research projects run out of the MIT Plasma Science and Fusion Center (PSFC)’s newly created Laboratory for Innovation in Fusion Technologies (LIFT). The expected investment in these research projects will amount to about $2 million over the following years.

    This is part of a broader engagement with fusion research and the Institute as a whole: Eni also announced a commitment of $50 million to a new private company with roots at MIT, Commonwealth Fusion Systems (CFS), which aims to make affordable, scalable fusion power a reality.

    “This support of LIFT is a continuation of Eni’s commitment to meeting growing global energy demand while tackling the challenge of climate change through its research portfolio at MIT,” says Robert C. Armstrong, MITEI’s director and the Chevron Professor of Chemical Engineering at MIT. “Fusion is unique in that it is a zero-carbon, dispatchable, baseload technology, with a limitless supply of fuel, no risk of runaway reaction, and no generation of long-term waste. It also produces thermal energy, so it can be used for heat as well as power.”

    Still, there is much more to do along the way to perfecting the design and economics of compact fusion power plants. Eni will fund research projects at LIFT that are a continuation of this research and focus on fusion-specific solutions. “We are thrilled at PSFC to have these projects funded by Eni, who has made a clear commitment to developing fusion energy,” says Dennis Whyte, the director of PSFC and the Hitachi America Professor of Engineering at MIT. “LIFT will focus on cutting-edge technology advancements for fusion, and will significantly engage our MIT students who are so adept at innovation.”

    Tackling fusion’s challenges

    The inside of a fusion device is an extreme environment. The creation of fusion energy requires the smashing together of light elements, such as hydrogen, to form heavier elements such as helium, a process that releases immense amounts of energy. The temperature at which this process takes place is too hot for solid materials, necessitating the use of magnets to hold the hot plasma in place.

    One of the projects PSFC and Eni intend to carry out will study the effects of high magnetic fields on molten salt fluid dynamics. One of the key elements of the fusion pilot plant currently being studied at LIFT is the liquid immersion blanket, essentially a flowing pool of molten salt that completely surrounds the fusion energy core. The purpose of this blanket is threefold: to convert the kinetic energy of fusion neutrons to heat for eventual electricity production; to produce tritium — a main component of the fusion fuel; and to prevent the neutrons from reaching other parts of the machine and causing material damage.

    It’s critical for researchers to be able to predict how the molten salt in such an immersion blanket would move when subjected to high magnetic fields such as those found within a fusion plant. As such, the researchers and their respective teams plan to study the effects of these magnetohydrodynamic forces on the salt’s fluid dynamics.

    A history of innovation

    During the 23 years MIT’s Alcator C-Mod tokamak fusion experiment was in operation, it repeatedly advanced records for plasma pressure in a magnetic confinement device. Its compact, high-magnetic-field fusion design confined superheated plasma in a small donut-shaped chamber.

    “The key to this success was the innovations pursued more than 20 years ago at PSFC in developing copper magnets that could access fields well in excess of other fusion experiments. The coupling between innovative technology development and advancing fusion science is in the DNA of the Plasma Science and Fusion Center,” says PSFC Deputy Director Martin Greenwald.

    In its final run in 2016, Alcator C-Mod set a new world record for plasma pressure, the key ingredient to producing net energy from fusion. Since then, PSFC researchers have used data from these decades of C-Mod experiments to continue to advance fusion research. Just last year, they used C-Mod data to create a new method of heating fusion plasmas in tokamaks which could result in the heating of ions to energies an order of magnitude greater than previously reached.

    A commitment to low-carbon energy

    MITEI’s mission is to advance low-carbon and no-carbon emissions solutions to efficiently meet growing global energy needs. Critical to this mission are collaborations between academia, industry, and government — connections MITEI helps to develop in its role as MIT’s hub for multidisciplinary energy research, education, and outreach.

    Eni is an inaugural, founding member of the MIT Energy Initiative, and it was through their engagement with MITEI that they became aware of the fusion technology commercialization being pursued by CFS and its immense potential for revolutionizing the energy system. It was through these discussions, as well, that Eni investors learned of the high-potential fusion research projects taking place through LIFT at MIT, spurring them to support the future of fusion at the Institute itself.

    Eni CEO Claudio Descalzi said, “Today is a very important day for us. Thanks to this agreement, Eni takes a significant step forward toward the development of alternative energy sources with an ever lower environmental impact. Fusion is the true energy source of the future, as it is completely sustainable, does not release emissions or waste, and is potentially inexhaustible. It is a goal that we are determined to reach quickly.” He added, “We are pleased and excited to pursue such a challenging goal with a collaborator like MIT, with unparalleled experience in the field and a long-standing and fruitful alliance with Eni.”

    These fusion projects are the latest in a line of MIT-Eni collaborations on low- and no-carbon energy projects. One of the earliest of these was the Eni-MIT Solar Frontiers Center, established in 2010 at MIT. Through its mission to develop competitive solar technologies, the center’s research has yielded the thinnest, lightest solar cells ever produced, effectively able to turn any surface, from fabric to paper, into a functioning solar cell. The researchers at the center have also developed new, luminescent materials that could allow windows to efficiently collect solar power.

    Other fruits of MIT-Eni collaborations include research into carbon capture systems to be installed in cars, wearable technologies to improve workplace safety, energy storage, and the conversion of carbon dioxide into fuel.

    See the full article here .

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  • richardmitnick 4:32 pm on March 9, 2018 Permalink | Reply
    Tags: , MIT,   

    From MIT: “MIT and newly formed company launch novel approach to fusion power” 

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    March 9, 2018
    David Chandler

    1
    Visualization of the proposed SPARC tokamak experiment. Using high-field magnets built with newly available high-temperature superconductors, this experiment would be the first controlled fusion plasma to produce net energy output. Visualization by Ken Filar, PSFC research affiliate.

    Goal is for research to produce a working pilot plant within 15 years.

    Progress toward the long-sought dream of fusion power — potentially an inexhaustible and zero-carbon source of energy — could be about to take a dramatic leap forward.

    Development of this carbon-free, combustion-free source of energy is now on a faster track toward realization, thanks to a collaboration between MIT and a new private company, Commonwealth Fusion Systems. CFS will join with MIT to carry out rapid, staged research leading to a new generation of fusion experiments and power plants based on advances in high-temperature superconductors — work made possible by decades of federal government funding for basic research.

    CFS is announcing today that it has attracted an investment of $50 million in support of this effort from the Italian energy company Eni. In addition, CFS continues to seek the support of additional investors. CFS will fund fusion research at MIT as part of this collaboration, with an ultimate goal of rapidly commercializing fusion energy and establishing a new industry.

    “This is an important historical moment: Advances in superconducting magnets have put fusion energy potentially within reach, offering the prospect of a safe, carbon-free energy future,” says MIT President L. Rafael Reif. “As humanity confronts the rising risks of climate disruption, I am thrilled that MIT is joining with industrial allies, both longstanding and new, to run full-speed toward this transformative vision for our shared future on Earth.”

    “Everyone agrees on the eventual impact and the commercial potential of fusion power, but then the question is: How do you get there?” adds Commonwealth Fusion Systems CEO Robert Mumgaard SM ’15, PhD ’15. “We get there by leveraging the science that’s already developed, collaborating with the right partners, and tackling the problems step by step.”

    MIT Vice President for Research Maria Zuber, who has written an op-ed on the importance of this news that appears in today’s Boston Globe, notes that MIT’s collaboration with CFS required concerted effort among people and offices at MIT that support innovation: “We are grateful for the MIT team that worked tirelessly to form this collaboration. Associate Provost Karen Gleason’s leadership was instrumental — as was the creativity, diligence, and care of the Office of the General Counsel, the Office of Sponsored Programs, the Technology Licensing Office, and the MIT Energy Initiative. A great job by all.”

    Superconducting magnets are key

    Fusion, the process that powers the sun and stars, involves light elements, such as hydrogen, smashing together to form heavier elements, such as helium — releasing prodigious amounts of energy in the process. This process produces net energy only at extreme temperatures of hundreds of millions of degrees Celsius, too hot for any solid material to withstand. To get around that, fusion researchers use magnetic fields to hold in place the hot plasma — a kind of gaseous soup of subatomic particles — keeping it from coming into contact with any part of the donut-shaped chamber.

    The new effort aims to build a compact device capable of generating 100 million watts, or 100 megawatts (MW), of fusion power. This device will, if all goes according to plan, demonstrate key technical milestones needed to ultimately achieve a full-scale prototype of a fusion power plant that could set the world on a path to low-carbon energy. If widely disseminated, such fusion power plants could meet a substantial fraction of the world’s growing energy needs while drastically curbing the greenhouse gas emissions that are causing global climate change.

    “Today is a very important day for us,” says Eni CEO Claudio Descalzi. “Thanks to this agreement, Eni takes a significant step forward toward the development of alternative energy sources with an ever-lower environmental impact. Fusion is the true energy source of the future, as it is completely sustainable, does not release emissions or long-term waste, and is potentially inexhaustible. It is a goal that we are increasingly determined to reach quickly.”

    CFS will support more than $30 million of MIT research over the next three years through investments by Eni and others. This work will aim to develop the world’s most powerful large-bore superconducting electromagnets — the key component that will enable construction of a much more compact version of a fusion device called a tokamak. The magnets, based on a superconducting material that has only recently become available commercially, will produce a magnetic field four times as strong as that employed in any existing fusion experiment, enabling a more than tenfold increase in the power produced by a tokamak of a given size.

    Conceived at PSFC

    The project was conceived by researchers from MIT’s Plasma Science and Fusion Center, led by PSFC Director Dennis Whyte, Deputy Director Martin Greenwald, and a team that grew to include representatives from across MIT, involving disciplines from engineering to physics to architecture to economics. The core PSFC team included Mumgaard, Dan Brunner PhD ’13, and Brandon Sorbom PhD ’17 — all now leading CFS — as well as Zach Hartwig PhD ’14, now an assistant professor of nuclear science and engineering at MIT.

    Once the superconducting electromagnets are developed by researchers at MIT and CFS — expected to occur within three years — MIT and CFS will design and build a compact and powerful fusion experiment, called SPARC, using those magnets. The experiment will be used for what is expected to be a final round of research enabling design of the world’s first commercial power-producing fusion plants.

    SPARC is designed to produce about 100 MW of heat. While it will not turn that heat into electricity, it will produce, in pulses of about 10 seconds, as much power as is used by a small city. That output would be more than twice the power used to heat the plasma, achieving the ultimate technical milestone: positive net energy from fusion.

    This demonstration would establish that a new power plant of about twice SPARC’s diameter, capable of producing commercially viable net power output, could go ahead toward final design and construction. Such a plant would become the world’s first true fusion power plant, with a capacity of 200 MW of electricity, comparable to that of most modern commercial electric power plants. At that point, its implementation could proceed rapidly and with little risk, and such power plants could be demonstrated within 15 years, say Whyte, Greenwald, and Hartwig.

    Complementary to ITER

    The project is expected to complement the research planned for a large international collaboration called ITER, currently under construction as the world’s largest fusion experiment at a site in southern France.

    ITER Tokamak in Saint-Paul-lès-Durance, which is in southern France

    If successful, ITER is expected to begin producing fusion energy around 2035.

    “Fusion is way too important for only one track,” says Greenwald, who is a senior research scientist at PSFC.

    By using magnets made from the newly available superconducting material — a steel tape coated with a compound called yttrium-barium-copper oxide (YBCO) — SPARC is designed to produce a fusion power output about a fifth that of ITER, but in a device that is only about 1/65 the volume, Hartwig says. The ultimate benefit of the YBCO tape, he adds, is that it drastically reduces the cost, timeline, and organizational complexity required to build net fusion energy devices, enabling new players and new approaches to fusion energy at university and private company scale.

    The way these high-field magnets slash the size of plants needed to achieve a given level of power has repercussions that reverberate through every aspect of the design. Components that would otherwise be so large that they would have to be manufactured on-site could instead be factory-built and trucked in; ancillary systems for cooling and other functions would all be scaled back proportionately; and the total cost and time for design and construction would be drastically reduced.

    “What you’re looking for is power production technologies that are going to play nicely within the mix that’s going to be integrated on the grid in 10 to 20 years,” Hartwig says. “The grid right now is moving away from these two- or three-gigawatt monolithic coal or fission power plants. The range of a large fraction of power production facilities in the U.S. is now is in the 100 to 500 megawatt range. Your technology has to be amenable with what sells to compete robustly in a brutal marketplace.”

    Because the magnets are the key technology for the new fusion reactor, and because their development carries the greatest uncertainties, Whyte explains, work on the magnets will be the initial three-year phase of the project — building upon the strong foundation of federally funded research conducted at MIT and elsewhere. Once the magnet technology is proven, the next step of designing the SPARC tokamak is based on a relatively straightforward evolution from existing tokamak experiments, he says.

    “By putting the magnet development up front,” says Whyte, the Hitachi America Professor of Engineering and head of MIT’s Department of Nuclear Science and Engineering, “we think that this gives you a really solid answer in three years, and gives you a great amount of confidence moving forward that you’re giving yourself the best possible chance of answering the key question, which is: Can you make net energy from a magnetically confined plasma?”

    The research project aims to leverage the scientific knowledge and expertise built up over decades of government-funded research — including MIT’s work, from 1971 to 2016, with its Alcator C-Mod experiment, as well as its predecessors — in combination with the intensity of a well-funded startup company. Whyte, Greenwald, and Hartwig say that this approach could greatly shorten the time to bring fusion technology to the marketplace — while there’s still time for fusion to make a real difference in climate change.

    MITEI participation

    Commonwealth Fusion Systems is a private company and will join the MIT Energy Initiative (MITEI) as part of a new university-industry partnership built to carry out this plan. The collaboration between MITEI and CFS is expected to bolster MIT research and teaching on the science of fusion, while at the same time building a strong industrial partner that ultimately could be positioned to bring fusion power to real-world use.

    “MITEI has created a new membership specifically for energy startups, and CFS is the first company to become a member through this new program,” says MITEI Director Robert Armstrong, the Chevron Professor of Chemical Engineering at MIT. “In addition to providing access to the significant resources and capabilities of the Institute, the membership is designed to expose startups to incumbent energy companies and their vast knowledge of the energy system. It was through their engagement with MITEI that Eni, one of MITEI’s founding members, became aware of SPARC’s tremendous potential for revolutionizing the energy system.”

    Energy startups often require significant research funding to further their technology to the point where new clean energy solutions can be brought to market. Traditional forms of early-stage funding are often incompatible with the long lead times and capital intensity that are well-known to energy investors.

    “Because of the nature of the conditions required to produce fusion reactions, you have to start at scale,” Greenwald says. “That’s why this kind of academic-industry collaboration was essential to enable the technology to move forward quickly. This is not like three engineers building a new app in a garage.”

    Most of the initial round of funding from CFS will support collaborative research and development at MIT to demonstrate the new superconducting magnets. The team is confident that the magnets can be successfully developed to meet the needs of the task. Still, Greenwald adds, “that doesn’t mean it’s a trivial task,” and it will require substantial work by a large team of researchers. But, he points out, others have built magnets using this material, for other purposes, which had twice the magnetic field strength that will be required for this reactor. Though these high-field magnets were small, they do validate the basic feasibility of the concept.

    In addition to its support of CFS, Eni has also announced an agreement with MITEI to fund fusion research projects run out of PSFC’s Laboratory for Innovation in Fusion Technologies. The expected investment in these research projects amounts to about $2 million in the coming years.

    “Conservative physics”

    SPARC is an evolution of a tokamak design that has been studied and refined for decades. This included work at MIT that began in the 1970s, led by professors Bruno Coppi and Ron Parker, who developed the kind of high-magnetic-field fusion experiments that have been operated at MIT ever since, setting numerous fusion records.

    “Our strategy is to use conservative physics, based on decades of work at MIT and elsewhere,” Greenwald says. “If SPARC does achieve its expected performance, my sense is that’s sort of a Kitty Hawk moment for fusion, by robustly demonstrating net power, in a device that scales to a real power plant.”

    See the full article here .

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